---
id: CVE-2026-89706
title: >-
  kernel: nfsd: Reset write verifier when async COPY writeback fails
  (CVE-2026-89706)
summary: >-
  A flaw was found in the Linux kernel's nfsd component. When an asynchronous
  (async) copy writeback operation fails, the server's write verifier is not
  properly reset. This can lead to a client incorrectly assuming that data has
  been made d…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-703
  - CWE-367
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T09:32:38+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89706'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532347'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89706'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89706'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89706.mbox
  - url: 'https://kernelcve.org/list/?q=CVE-2026-89706'
  - url: 'https://git.kernel.org/stable/c/cc5f7cef0659a27c13dd33edd8e2f79257b095c6'
  - url: 'https://git.kernel.org/stable/c/c6d2f6372c7e0f76b9c148ff7696aec64da0b5b7'
  - url: 'https://git.kernel.org/stable/c/8a08ffe73eb2aa6bc6f88763da7e2b55bab6493a'
  - url: 'https://git.kernel.org/stable/c/6b13d26cc21b6320a3c61d5e4cee2ce9a589b181'
  - url: 'https://git.kernel.org/stable/c/31d4d0a62ec4bafbcdbad142f11ab1f90794b1d0'
  - url: 'https://git.kernel.org/stable/c/591134e059e3456180244a826d6917cdc183140b'
  - url: 'https://git.kernel.org/stable/c/bf0cd31a9abcb728c17d79b4c2cc533612a8b6af'
  - url: 'https://git.kernel.org/stable/c/f5cb2276954cb80987a93ef9f9dfbfdbfc0f10b9'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00526
epssPercentile: 0.44376
scores:
  vendor: 7
  cna: 7.5
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

A flaw was found in the Linux kernel's nfsd component. When an asynchronous (async) copy writeback operation fails, the server's write verifier is not properly reset. This can lead to a client incorrectly assuming that data has been made durable, resulting in the silent loss of data that was intended to be copied.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89706.json)

**kernel: nfsd: Reset write verifier when async COPY writeback fails** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-10-21.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope

Workarounds / mitigations:

- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.